Karyotype and chromosomal banding pattern in Heteropeza pygmaea.

The chromosomes of somatic and germ line cells of female embryos produced by paedogenesis were studied. The haploid set in somatic cells consists of one long submetacentric chromosome, one large acrocentric, one medium metacentric and two small acrocentrics. The length vs arm index karyogram makes it possible to distinguish all but the two pairs of small acrocentric chromosomes. --Atempts were made to develope a method for banding pattern visualization. The best result was obtained using trypsin which induced banding in the chromosomes of the somatic cells and occasionally also the germ line cells. The resulting banding patterns were frequently not identical in members of a chromosome pair. There was also a variation between metaphases within an embryo as well as from different embryos. Some tentative explanations for these results are discussed.